Installation of flexible lining with flexible collar for lining lateral pipelines

ABSTRACT

A method for installation of a flexible resin impregnable liner for lining a lateral pipe which leads into a main pipe having at one end a flexible collar for installation at the location where the lateral liner meets the main, wherein after installation the collar extends along the interior of the main seating against the opening of the lateral. The flexible liner is installed by inserting the liner into the lateral pipe and using fluid under pressure to expand the lining against the lateral wall to form seals with the collar at the lateral/main pipe junction.

[0001] This invention relates to the lining of pipelines or passageways,using flexible tubular materials which are impregnated with curablesynthetic resin and which, when placed in position lining the pipelineor passageway are held by fluid pressure against the pipeline orpassageway surface until the resin cures to a hard condition leaving ahard lining pipe lying on the pipeline or passageway surface.

[0002] The most widely practised method using such resin impregnatedlinings is disclosed in British Patent No. 1449455 from which it will beseen that the impregnated lining is applied to the pipeline orpassageway surface by eversion of same into the pipeline or passageway,using fluid pressure.

[0003] The present invention is concerned with lining pipelines whichare called “laterals” insofar as they enter sidewise a main pipeline orpassageway, such as a main sewer. Of any particular main line, there maybe a plurality of laterals entering the main line, and it frequentlyarises that the laterals have to be lined by means of a resinimpregnated tube. Using existing methods for lining laterals, it is notpossible to perform any lining operation of a second or subsequentlateral whilst the lining in one lateral is being cured. As the curetime may take up to 5 or 6 hours, if a section of main line having say 5laterals to be lined is involved, the minimum total time to line alllaterals will be in the order of 25 to 30 hours. As these liningoperations are required to be carried out during the night for purposesof convenience, it is often the case that the completion of the work hasto take place over several evenings and therefore the work crew mustdepart the site and return at a later date to complete the work.

[0004] The present invention is concerned with providing an arrangementwherein the completion of a plurality of lateral lining operations maybe effected in a much shorter period.

[0005] In accordance with the present invention, a plurality of lateralsmeeting a common main line are lined by inserting resin impregnatedlinings into said laterals and to hold same in position by fluidpressure whilst curing of the resin takes place, and after insertion ofeach lining, a seal arrangement at the location where the lateral meetsthe main line enables the second and subsequent laterals to be linedwhilst the first or previosuly inserted lining is held in position andis being cured.

[0006] The seal arrangement may comprise a flexible bag which ispressurised with the medium which urges the lining against the lateralsurface so as to prevent escape of the pressurising medium, but such bagallowing pressure fluid supplying pipes to pass to the inside or outsideof the bag and to other lateral connections downstream of the bag in themain pipe whereby such other laterals may be lined by the eversion thereinto of a resin impregnated lining tube, the holding of the lining tubeto the lateral surface by fluid pressure, and a sealing bag retainingthe lining in position and forming a seal between the lateral and themain line.

[0007] It will be seen that by using the method, the linings for thelaterals can be inserted sequentially, and held in installed positionunder pressure, and cured simultaneously. A plurality of laterals can belined and cured in a total time equal to the time it takes to line onelateral multiplied by the number of laterals plus the curing time forone of the lateral linings which total time in the case of 5 lateralsmay be in the order of 8 hours, which is a considerable reduction fromthe 25-30 hours which are required for the lining of 5 laterals by theconventional method. For example therefore the lateral lining on anyparticular contract may be capable of being completed in one evening asopposed to being completed in stages over two or three evenings.

[0008] Embodiments of the invention will now be described, by way ofexample, with reference to the accompanying diagrammatic drawings,wherein:

[0009]FIG. 1 is a diagrammatic side elevation showing the method bywhich a lateral is lined in accordance with the method of the invention;

[0010]FIG. 2 is a sectional elevation taken on the line II-II;

[0011]FIG. 3 is an enlarged sectional view of the detail ringed III inFIG. 1;

[0012]FIG. 4 is an enlarged sectional view of the detail ringed IV inFIG. 1;

[0013]FIG. 5 is a sectional side view of an alternative form ofapparatus for carrying out the method of the invention.

[0014]FIG. 6 is an end view of the arrangement shown in FIG. 5; and

[0015]FIG. 7 is a perspective view of the lining tube used in the methodof FIGS. 5 and 6.

[0016] Referring to the drawings, in FIG. 1 a main line 10 isintersected by a lateral 12 which is to be lined in accordance with afirst method of the invention.

[0017] For the lining operation, a resin impregnated flexible liningtube 14 has a beaded end 16 which is reinforced, and forms a ring whichseats against the opening of the lateral 12. The tube 14 is loadedinside a carrier tube 18. Carrier tube 18 has one end 20 anchored to anelbow pipe 22, and to the other end of the elbow 22 is connected acontainment tube 24. A disc 26 seals the other end of the containmenttube, but extending through the disc is a pressure hose 28 and a bleedhose 30.

[0018] The pressure hose 28 and bleed hose 30 can slide through the disc26 as insertion of the lining tube 14 takes place as will be explained.

[0019] If reference is made now to FIG. 4, as shown, the tail end of thecarrier tube 18 is closed around the bleed hose 30, and the pressurehose 28 is connected to the closed end of the carrier tube 18. The endof the lining tube 14 stops short of the end of the carrier tube so thatthe lining tube can be left in position lining the lateral 12.

[0020] The method of insertion comprises the introduction ofpressurising fluid, water or gas, through the pressure hose 28 into thespace between the containment tube 24 and the carrier tube 18 with theresult that the carrier tube 18 and the lining tube 14 are everted asshown at 32 in FIG. 1 into the lateral 12, the lining tube 14 beingpresented to the lateral surface. The assembly of tubes 14 and 18therefore everts into the lateral 12 and the pressure hose 28 and thebleed hose 30 are pulled through the containment tube, through the elbow22 and up to the top end of the lateral. The portion 30A of the bleedhose projects out of the end of the eversion face so that if any watercollects above the lining, it can bleed through end 30A, which isprovided with apertures 34 for this purpose, out of the tube 30 and backto drain so that there will be no undesirable collection of liquid inthe lateral whilst lining is taking place.

[0021] The pressure fluid which is supplied by the hose 28 leaks throughan aperture 36 in the elbow 22 and pressurises a bag or bladder 38surrounding the elbow as shown. The bladder is therefore inflated so asto seal against the main line 10 and to seal the end 16 of the lining.The aperture is provided with or acts as a pressure reduction means sothat whilst the everting pressure may be of the order of 20 p.s.i., thepressure in the bag or bladder 38 is much lower e.g. in the order of 5p.s.i. The bladder 38 remains pressurised as long as the pressure ismaintained inside the everted lining and carrier tube. As soon as thisposition has been reached, a towing assembly 40 which is used forpositioning the elbow 22 by being connected thereto through a link 42fast with elbow 22, is released from that link insofar as, as shown inFIG. 3, the link 42 has a socket 44 in which engages a centralising pin46. The wall of the socket 44 has aligned apertures 48, 50 in which pegs52 and 54 engage, these pegs being carried by pivotable jaws 56 and 58.The jaws 56 and 58 are connected to the clamping device 60 havingswingable arms 62 and 64 on the ends of which are provided guide rollers66 and 68. As the bladder 38 inflates, the rollers 66 which are heldinwardly by spring action are caused to pivot to the position shown inFIG. 1 which has the effect of moving the jaws 56 and 58 apart to removethe pegs 52 and 54 from the apertures 48 and 50 and the positioningdevice 40 and the device 60 with the rollers and jaws can be detachedfrom the bladder and the connecting tube 42 so that it can be pulledalong the line 10 away from the inflated bladder.

[0022] A series of additional pressure pipes and corresponding bleedpipes 70, 72 (four in all) extend to the outside of the bladder 38 andare removably attached to the positioning device 40. Device 40 is movedto the other end of the main line 10 and a second assembly comprisingelbow 22, bladder 38, containment tube 24, sealing disc 26 and thecarrier tube and lining 18 and 14 with bladder 38 is connected to thepositioning device (and one of the additional pressure/bleed pipe pair)which is again moved back into the main line 10 until the next lateralto be lined is reached when the device is placed in register therewithso that by appropriate pressurising of the assembly as described inrelation to FIG. 1, the lining tube can be inserted into position in thelateral. When this process has been completed, the procedure is againrepeated so that all five laterals can have lining tubes placed thereinand the lining tubes can be cured simultaneously.

[0023] To effect the curing, it may be necessary to circulate hot water,steam or hot air through the pressurising hoses 28, 70 and 72 if theresin is of the heat cure type.

[0024] When curing has been completed, it is simply a matter ofreleasing the pressure in each of the bladders 38 which will thencollapse, and each can be removed from the main line 10 by pulling onthe pressure hose 28, 70 or 72 as the case may be. The retraction ofsuch hose retracts the carrier tube 18 from inside the lateral, leavingthe rigid lining tube 14 in position.

[0025] In the alternative arrangement shown in FIGS. 5, 6 and 7, themethod of operation is the same as that described in relation to FIGS.1-4, and only the structure of the bladder is varied in order to make iteasier for the additonal pressure/bleed pipes to pass the bladderassembly whilst it is inflated.

[0026] Thus, the bladder is in the form of diametrically oppositeinflatable pillows 80, 82 which are carried on inner diametricallyopposite plates, 84, 86 connected to the elbow 22 by being boltedthereto by bolts 88. Plate 86 is carried by the elbow 22 on a radial leg90 which is adjustable in length so that the arrangement can be adjustedto suit pipes of different diameters. Pillow 80 has a hole, 92 thereinthrough which the elbow pipe 22 passes the pipe 94 which extends fromthe elbow 22 forms passage for the everting medium and also carries thecoupling 42. Pipes 96, 98 connect the interior of the pipe 94 and thepillows 80, 82. The aperture 36 is also shown in FIG. 5. The operationof the arrangement of FIGS. 5, 6 and 7 will be understood from theprevious description of the embodiment of FIGS. 1-4. The lining 14 andthe carrier tube 18 are inverted by pressurising the interior of elbow22 and at the same time by passage of the pressurising medium throughhole 36, pipe 94, and pipes 96, 98 inflation of the pillows 80, 82 toseal the lateral aperture whilst eversion takes place. The additionalpressure/bleed pipes 70, 72 can pass between the pillows easily as shownin FIG. 6 in dotted lines. Whilst pillow 80 seals the lateral, pillow 82forms a reaction means.

[0027] The lining tube 14 in the FIG. 7 arrangement as shown has acollar, 100 which is preferably a sealed envelope containing a resinabsorbent material which is impregnated with curable synthetic resinsimilar to the tube itself. As the lining tube 14 cures so the collarwill also cure and the collar remains in place around the lateralaperture.

[0028] The present invention provides a system whereby a plurality oflateral linings may be cured simultaneously thereby reducing the overallcure time in a contract where a number of laterals have to be lined.

1. A method of lining a lateral pipe leading into a main pipe, wherein aresin impregnated lining is inserted into the lateral pipe using a fluidmedium under pressure, and wherein a seal arrangement forms a seal atthe location where the lateral meets the main pipe as curing of theresin takes place.
 2. A method according to claim 1, wherein the seal isformed by an inflatable means, said means being inflated by the fluidmedium used for inserting the lateral lining, but at a lower pressure.3. A method according to claim 1 or 2, wherein the fluid medium issupplied to insert the lateral lining by means of a pressure pipe, andat least one additonal pressure pipe extends past the seal arrangementso that pressure fluid can be applied to another lateral lining remotefrom the first mentioned lateral whilst curing of the first mentionedlateral lining is taking place.
 4. A method according to claim 1, 2 or3, wherein the seal arrangmeent comprises an elbow pipe through whichthe lateral lining is everted to be inserted into the lateral, and theseal arrangement is connected to the elbow.
 5. A method according toclaim 4 when taken with claim 2, wherein the inflatable means comprisesa bag or bladder which is inflated against the main pipe surface.
 6. Amethod according to claim 5, wherein the bag or bladder is in the formof a pair of spaced diametrically opposed inflatable pillows.
 7. Amethod according to any preceding claim wherein the lining tube isprovided with a collar which is applied to the location at which thelateral meets the main pipe, and the lining is of finite length and isopen ended.
 8. Apparatus for inserting a resin impregnated lining into alateral pipe which leads to a main pipe, comprising an elbow pipe bywhich the lining may be inverted using fluid medium under pressure intothe lateral from the main pipe, said elbow having connected thereto aninflatable sealing arrangement whereby the elbow may be locked inposition in the main pipe by means of said fluid medium, and so that apressure pipe may extend along the main pipe past the sealingarrangement so that a further lining may be inserted into a furtherlateral whilst the sealing arrangement holds the elbow in position inthe main pipe and the resin impregnated first mentioned lining cures.